Clathrate of chlorine dioxide

ABSTRACT

A clathrate is provided that includes chlorine dioxide. The clathrate is effective for entrapping chlorine dioxide to provide a dry solid material. The clathrate is formed as a reaction product of saccharides, organic acids, and the addition of chlorine dioxide and enhancers.

The present invention relates to clathrates that include chlorine dioxide and methods for their production and use. More particularly, the invention relates to clathrates that are formed from chlorine dioxide, saccharides, and organic acids.

BACKGROUND

Chlorine dioxide is of considerable industrial importance and has found use as a disinfectant and in the bleaching of wood pulp, fats, oils and flour, and more recently for the sterilization of anthrax. Generally, chlorine dioxide is used as a bleaching agent and for removing tastes and odors from water and the like liquids. More recently, it has been used as an anti-pollutant for disinfecting drinking water.

For several of the established uses of the chlorine dioxide, it is desirable to produce the gas in situ so that the chlorine dioxide, upon formation, can be directly put to use either in gaseous form or, after absorption, in the form of an aqueous solution. In many instances, the use of chlorine dioxide solution rather than in the gaseous form is preferred. Chlorine dioxide is absorbed in water and forms chlorous acid, from which the gas can be readily expelled by heating. The presence of chlorous acid in an aqueous solution indicates a reaction of chlorine dioxide with water.

Several processes have previously been proposed for producing chlorine dioxide. Attention is thus directed to U.S. Pat. Nos. 3,648,437, 3,695,839, 3,828,097, 4,877,500, 4,874,489 and 3,754,079, all of which are directed to the production of chlorine dioxide or chlorous acid from which the chlorine dioxide can be expelled.

SUMMARY

The present invention is directed to a clathrate that includes ClO₂. The clathrate is effective for entrapping ClO₂ to provide a dry solid material. The clathrate containing the ClO₂ releases ClO₂ when the clathrate is contacted with water, heated in excess of about 37° C., ground up or exposed to a combination of heat and moisture. The solid clathrate material allows for ease of handling of ClO₂ without generation equipment or gas under compression.

In one aspect, the clathrate includes an amount of ClO₂ that will provide an amount of ClO₂ effective for disinfecting the medium in which it is used. This amount may varying depending upon the type of medium to be disinfected. Generally, the clathrate includes at least about 0.1 weight percent ClO₂ and in an important aspect, from about 0.1 to about 10 weight percent ClO₂, preferably about 0.4 to about 3 weight percent ClO₂ based on the weight of the clathrate.

The clathrate is formed as a reaction product of monosaccharides, disaccharides, polysaccharides and mixtures thereof, and one or more organic acids. During formation of the clathrate, the reaction mixture is free of water such that less than about 0.5 weight percent water, preferably less than about 0.1 weight percent water, is present in the reaction mixture. In this aspect, the clathrate includes at least about 9 weight percent monosaccharide and in an important aspect, from about 9 to about 74.5 weight percent monosaccharide, preferably about 20 to about 70 weight percent monosaccharide, based on the weight of the clathrate. The clathrate further includes at least about 25 weight percent organic acids and in an important aspect, from about 25 to about 80 weight percent organic acids, preferably about 31 to about 80 weight percent organic acid, based on the weight of the clathrate.

The present invention is further directed to a method for forming a clathrate of ClO₂. In accordance with the method, at least about 25 weight percent organic acids, based on the weight of the clathrate, is blended with a saccharide to form an organic acids/saccharides blend. The method is effective for providing a clathrate that includes at least about 9 weight percent saccharide, based on the weight of the clathrate, and in an important aspect, from about 9 to about 74.5 weight percent saccharide, based on the weight of the clathrate. The organic acid/saccharide blend is contacted with a source of ClO₂ to provide a clathrate of ClO₂. The source of ClO₂ may be in the form of ClO₂ gas or a salt of ClO₂. In this aspect, the method of the invention is effective for providing a clathrate that includes at least about 0.1 weight % ClO₂, based on the weight of the clathrate, and in an important aspect, from about 0.4 to about 10 weight % ClO₂, based on the weight of the clathrate.

The clathrate of the invention may be utilized as a biocide, for the disinfection or treatment of water, as a bleaching agent, or as a oxidizing agent. In one aspect of the invention, a clathrate containing ClO₂ is contacted with aqueous composition. The clathrate of ClO₂ is effective for reducing a microbial count in the aqueous composition by at least about five logarithmic units. The clathrate of ClO₂ is effective for providing a concentration of ClO₂ in the aqueous composition of at least 0.2 ppm.

In another aspect, the formation of ClO₂ can be achieved from the reaction of RClO₂ under UV irradiation. In one aspect, a RClO₂ solution is irradiated with a UV source for a time and intensity effective for forming ClO₂, wherein R is an ion such as Na, K, Ca or Mg (ionizable).

In another aspect, ClO₂ is formed by combining a stream of RClO₂ and an acid stream in an amount effective for providing an R ion concentration equivalent to an acid concentration, wherein R is Na, K, Ca or Mg. The combined stream is irradiated with a UV source for a time effective for forming ClO₂. These methods allow for the production of ClO₂ with less equipment and allows for production of ClO₂ in small amounts and in batch.

DETAILED DESCRIPTION

The clathrate of the present invention is formed from the reaction product of ClO₂, saccharide and organic acid. The clathrate acts as a cage which holds the ClO₂ until some external influence acts on its release. In the clathrate, the interaction between the molecules may occur via Vanderwalls forces or physical capturing. There is no covalent bonding, but rather a weak hydrogen bond may be present. The ClO₂ gas is trapped within the clathrate but is not covalently bonded to the structure.

As used herein, “clathrate” refers to a compound formed by the inclusion of molecules of one kind in cavities of the crystal lattice of another.

The clathrate of the present invention is anhydrous. As used herein “anhydrous” refers to being free from water and especially water of crystallization; destitute of water, as anhydrous salts of acids. In this aspect, the clathrate has less than about 0.5 weight percent water, based on the weight of the clathrate.

Sources of ClO₂

The clathrates of the present invention include ClO₂. The ClO₂ may be provided in the form of a gas, or may be formed in situ.

ClO₂ gas may be contacted directly with saccharide and organic acid to form a clathrate that includes ClO₂. ClO₂ in the form of a gas may be contacted with a blend of saccharide and organic acid by bubbling or sparging the ClO₂ gas through the saccharide/organic acid blend.

The ClO₂ may be provided in the form of a salt of yClO_(x), where x is 1, 2, 3 or 4, and y is Na, K, Mg, or Ca.

ClO₂ may be manufactured from the reaction of sodium chlorite (NaClO₂) with Cl₂ (g) via gaseous chlorination or from the reaction of sodium hypochlorite (NaOCl) with HCl and NaClO₂. U.S. Pat. Nos. 4,877,500 and 4,874,489, which are hereby incorporated by reference describes the formation of ClO₂ in situ from the reaction of Cl₂ and O₂ gases with UV radiation. Two percent w/v Cl₂ (aqueous)with O₂ under UV radiation can also generate ClO₂. The alkali metal of ClO₂ (MClO₂) or MClO can be converted to ClO₂ under specified UV conditions. The end product, ClO₂, is a yellowish-green, pungent gas with a density 2.4 times that of air. It is water soluble and decomposes under exposure to water, pressure, heat, and noise. When ClO₂ comes in contact with water, HClO₂ is generated. Typically, when ClO₂ is generated, it is used on location without transportation and labeling concerns.

ClO₂ may be generated from the reaction of RClO₂ under UV irradiation. In this aspect, R may be Na, K, Ca, or Mg. In an important aspect, R is Na. The reaction of NaClO₂ with UV is reversible method (reaction can proceed to the left or right) when the UV source is not applied or interrupted by failure. In this aspect, UV is applied for a time effective to form ClO₂. UV may be applied for at least about one minute. The duration of UV exposure may depend on the depth of the solution or solid that the UV has to penetrate. The reaction is immediate after penetration of the mixture. The intensity of the UV source should be at least about 4,000 microwatts/square centimeter at one inch, preferably at least about 20,000 microwatts/square centimeter at one inch. The reaction proceed quickly and is effective to provide a yield of ClO₂ of at least about 90%.

The ClO₂ can be separated from the water mixture by displacement with a stream of air. This causes the reaction to go to completion or become a nonreversible method. The reaction proceeds to the right under the described aeration conditions.

The nonreversal of this reaction can be also eliminated by the addition of an H⁺ ion concentration equivalent to the R⁺ ion concentration, with cognizance regarding toxicity of the acid salt formed as well as availability and solubility. Any H⁺ source can be used, or any organic, inorganic or intermediate chemicals that produce H⁺ when added to water, such as chlorine. If the UV source fails, the reaction to form ClO₂ does not reverse to the original concentrations of RClO₂ and RClO₃ ⁻.

The reaction speed is fast and provides a good source of ClO₂ for incorporation into the clathrate.

Saccharides

Clathrates are formed from saccharides and anhydrous acids. The saccharides may be provided initially in the form of monosaccharides, disaccharides, and/or polysaccharides. Examples of monosaccharides useful in the present invention include glucose, ribose, fructose, galactose, sorbose, tagalose, allose, altrose, mannose, gulose, idose, talose and mixtures thereof. Example disaccharides useful in the present invention include combinations of monosaccharides such as for example sucrose, lactose, maltose and mixtures thereof. Polysaccharides useful in the present invention include homopolysaccharides and heteropolysaccharides, for example, cellulose and starch. Where the clathrate is to be utilized in connection with an end product for human consumption, the saccharide may be a food grade saccharide.

Organic Acids

The clathrates of the present invention include organic acid. Organic acids useful in the present invention include citric acid, ascorbic acid, lactic acid, phosphoric acid, fumaric acid, malic acid, tartaric acid, acetic acid, proprionic acid, boric acid and mixtures thereof. Essentially, these acids must be nontoxic in order to be used for waste water and food applications. Where the clathrate is to be utilized in connection with an end product for human consumption, the organic acid may be a food grade organic acid. A single acid or mixture of acids my be utilized.

Optional Ingredients

EDTA: In an alternative aspect, EDTA (ethylenediamine tetra-acetic acid) may be utilized to form the clathrate. EDTA causes an effective chelation to the structure which increases its strength and make the structure larger as compared to clathrates that are not formed with EDTA. In this aspect, from about 0 to about 3 weight percent EDTA, based on the weight of the clathrate, is blended with saccharide and organic acid.

Surfactant: In another alternative aspect, a compound that includes hydrophillic and hydrophobic radicals, such as a surfactant, may be utilized to form the clathrate. Examples of surfactants useful in the present invention include Triton and Tergitol. The use of surfactant is effective for increasing the concentration of ClO₂ in the clathrate as compared to a clathrate that is not formed with surfactant. In this aspect, from about 0 to about 4 weight percent surfactant, based on the weight of the clathrate, is blended with saccharide and organic acid.

Polymers: Clathrates of the invention may be coated with polymer to protect against water absorption and percussion for support. Examples of useful polymers include water soluble polymers (ie. poly(vinylchloride) or PVA). Anhydrous polymers may be coated onto the clathrates after their formation.

Method for Making a Clathrate Containing ClO₂

The clathrate of the present invention may be made by blending organic acid and saccharide. The blend of organic acid and saccharide is then contacted with a source of ClO₂. The ClO₂ clathrate should be made at temperatures less than 37° C. to reduce the risk of the saccaride melting or changing from a solid (crystalline product) to an amorphous or liquid form. The colder the mixture, the higher the ClO₂ concentration in the clathrate. The reaction to form the clathrate of the invention is generally described below.

Methods for Use

The clathrate of the present invention allows for the release of ClO₂ gas from the clathrate structure by the following means:

-   -   dissolution in water or water-containing media,     -   heating in excess of 37° C.,     -   percussion of the crystal by grinding or heavy force,     -   or combination of heating and dissolution (hot water).

In a typical use, the dry clathrate containing ClO₂ is added to a liquid. The clathrate will begin releasing ClO₂ once the water content of the clathrate exceeds about 0.5 weight percent, based on the weight of the clathrate.

The following examples illustrate methods for carrying out the invention and should be understood to be illustrative of, but not limiting upon, the scope of the invention which is defined in the appended claims.

EXAMPLES Example 1 Test Method

In each of the examples, ClO₂ gas is measured spectrophotometrically and compared to standards of ClO₂ gas patterns with their wavelength peak at 343 nanometers. The ClO₂ gas content is reported in weight percent. The color of the ClO₂ clathrate can vary from a yellow to brown to black color. The ClO₂ concentration can be determined by colorimetry. The crystals of the ClO₂ clathrate can be separated gravimetrically, or by color. The density of the ClO₂ clathrate increases as the inclusion body, ClO₂, is trapped in the clathrate.

Example 2 Preparation of Clathrate

1.0 grams of citric acid is admixed with 2.0 grams of glucose in a mortar and pestle. The ClO₂gas (reference U.S. Pat. No. 4,874,489) is allowed to disperse through the mixed crystal, while being covered with an expandable membrane. After standing for 30 minutes, the membrane is removed. The yellow crystals are aliquoted and tested for ClO₂ spectrophotometry over 30 days. The results of this example are shown in Table 1. The level of ClO₂ incorporation as a function of time is presented in Table 1. TABLE 1 Time Identification of ClO₂* 20 minutes positive 2 hours positive 24 hours positive 48 hours positive 72 hours positive 144 hours positive 10 days positive 30 days positive *Positive or negative identification of ClO₂ by spectrophotometry at 343 nm with expected wave pattern.

Varying concentrations of ClO₂ were attempted with a resultant equilibrium of clathrate and citric acid yielding 1.9 weight percent ClO₂.

Example 3 Preparation of Clathrate Using EDTA

EDTA (10 grams) and glucose (10 grams) are admixed in a mortar and pestle. Chlorine dioxide (ClO₂) gas (adsorbed by the mixture) was added similarly to Example 2. Cellulose can be substituted for glucose yielding similar results. The results of this experiment indicate that the equilibrium of ClO₂ to EDTA was consistently less than 0.8 weight percent.

Example 4 Preparation of Clathrate Using Tartaric Acid

EDTA (10 grams), glucose (10 grams) and tartaric acid (5 grams) are admixed in a mortar and pestle. Chlorine dioxide gas was adsorbed by the mixture similarly to Example 2. The results of this experiment and a second trial indicate that the equilibrium of ClO₂ to tartaric acid is 0.4-1.2 weight percent.

Example 5 Preparation of Clathrate with Organic Acids

EDTA (10 grams), glucose (10 grams), and one of the following acids, 25 grams boric acid or 30 grams lactic acid, are admixed in a mortar and pestle. Chlorine dioxide gas is adsorbed by the mixture similarly to Example 2. The results of these experiments indicate that the equilibrium of ClO₂ to the above acids is 0.08-1.2 weight percent. In the case of lactic acid, a hygroscopic agent such as silica gel is added to absorb the water along with a glucose buffer (10 grams NaCl), followed by the adsorption or until adsorption ceases of ClO₂ gas or sodium chlorite at equal weight of acid concentration used. Table 2 demonstrates the use of different organic acids for ClO₂ clathrate formation on a weight percent basis. TABLE 2 Organic Acid ClO₂ (weight percent) Citric acid 1.9 EDTA 0.08 Tartaric acid 0.08-1.2 Boric acid, lactic acid, etc. 0.08-1.2

In Examples 2-4, the clathrate is physically separated from the other crystalline material (visual color separation). The crystalline clathrate material is yellow in color. The results of experiments 2-4 based on inclusion of ClO₂ are presented in Table 2. The melting point is approximately 153° C, with a water solubility of approximately 60 percent at 20° C. The ClO₂ clathrate is very hygroscopic upon standing.

Example 6 Preparation of the ClO₂ Clathrate from a Chlorite and an Organic Acid with Glucose Buffer

0.5 grams of NaClO₂ is admixed with 2.0 grams of granulated sugar in a mortar and pestle. 5.0 grams of the monohydrate of citric acid is also added to the above mixture. Upon standing, a crystalline substance is formed and spectrophotometry determined the concentration of ClO₂ to be about 1.9 weight percent.

Example 7 Preparation of the ClO₂ Clathrate with Surfactant

Tergitol (2-5 grams) and/or Triton 100 (2-5 grams) (long chain lauryl sulfonate compounds) are added to Example 4. The results of this experiment indicate that the equilibrium of ClO₂ to EDTA with Tergitol and/or Triton 100 reached 1-3 weight percent. The levels varied as a function of the concentration of Tergitol and/or Triton.

Example 8 Preparation of the ClO₂ Clathrate with NaClO₂

1.0 grams of citric acid is admixed with 2.0 grams of glucose in a mortar and pestle. The ClO₂ gas in this experiment originates from NaClO₂ and HCl which is adjusted to a pH=4.5 with a bicarbonate buffer. This mixture is added to the monosaccharide organic acid mixture. The ClO₂ is allowed to disperse through the mixed crystal, while being covered with an expandable membrane. After standing for 30 minutes, the membrane is removed with similar results of ClO₂ clathrate production as described in the previous examples. Similar results can be achieved in substituting glucose for cellulose.

Example 9 Preparation of ClO₂ with NaClO₂ and UV Radiation

A) A solution of 10% NaClO₂ by weight is irradiated with UV yielding a solution of 7.8 weight percent ClO₂ in water after air displacement and water resorption.

B) A solution of 10% NaClO₂ by weight is irradiated with UV. After 20 minutes, the UV is interrupted followed by the sample being capped and refrigerated. The solution contained 70 weight % NaClO₂ in water after 15 minutes.

C) A stream of 10% by weight NaClO₂ plus a 15% by weight solution of citric acid meet concurrently in a tube containing a UV source. The streams were irradiated for 20 minutes and then interrupted. The samples were capped and refrigerated yielding the results presented in Table 3. TABLE 3 Time (hours) ClO₂ (weight percent) 2 7.6 23 7.4 40 7.2 70 6.6

D) A 10% NaClO₂ solution was fed concurrently with a 3% by weight solution of citric acid and irradiated with UV for 20 minutes. The results are presented in Table 4. TABLE 4 Time (hours) ClO₂ (weight percent) 1 7.6 2 6.1 6 5.0 24 2.0

E) A 5% NaClO₂ solution was fed concurrently with a 20% by weight solution of citric acid and irradiated with UV for 20 minutes. The results are presented in Table 5. TABLE 5 Time (hours) (Weight percent) 2 3.0 ClO₂ 2 0.4 OCl⁻ 2 0.1 Cl₂ 2 1.0 Chloramine 6 2.0 ClO₂ 6 1.0 OCl⁻ 6 1.0 Chloramine

Example 10 Concentration of ClO₂ Crystals with the use of Solvents

The addition of solvents before adsorption or absorption of ClO₂ in the clathrate was studied. Methyl alcohol absolute was added to the mixtures described above with the resultant mixtures being air dried having average ClO₂ concentration increases as noted in Table 6. The mixtures containing different acids are presented. TABLE 6 Acid Average % Increase Citric acid 4-7 Lactic acid 5 EDTA 3-5 Tartaric acid 6

Ethyl alcohol absolute was substituted for absolute methyl alcohol yielding similar results. The addition of ethers such as ethyl ether or petroleum ether resulted in no appreciable differences. In the case of boric acid with ethyl ether, a reduction of 4-5% ClO₂ was noted. Water soluble oils in place of ethers or alcohols yielded an average increase of ClO₂ in the clathrate of 5-8%.

Example 11 Addition of desiccants to ClO₂ clathrates

The stability of the ClO₂ clathrates is increased by the addition of desiccants to the crystal clathrate. Desiccants aid in the removal of water especially during storage. Five grams of glucose citric acid clathrate is ground in a mortar and pestle with 5 grams of silica gel. The resulting mixture was exposed to different conditions and compared to a 5 gram sample of non-desiccant containing glucose citric acid clathrate. The sample conditions are described in Table 7. The resultant ClO₂ clathrate quantities are reported in grams. A comparison of the samples with and without desiccant are noted below. TABLE 7 Time/ Condition 0 24 hours 1 week 6 weeks 12 weeks U/A(w/o) 5 5 5 4.5 4.2 U/A(w) 2.5 2.5 2.5 2.5 2.5 U/A/H(w/o) 5 5 4.5 4.6 3.6 U/A/H(w) 2.5 2.5 2.5 2.5 2.5 P(w/o) 5 5 5 5 5 P(w) 2.5 2.5 2.5 2.5 2.5 C(w/o) 5 5 5 5 5 C(w) 2.5 2.5 2.5 2.5 2.5 U/A(w/o): uncapped and exposure to air without silica gel U/A(w): uncapped and exposure to air with silica gel U/A/H(w/o): U/A and heated to 60° C. without silica gel U/A/H(w): U/A and heated to 60° C. with silica gel P(w/o): 25 psi capped without silica gel P(w): 25 psi capped with silica gel C(w/o): Cooling to 2.0° C. without silica gel C(w): Cooling to 2.0° C. with silica gel

Numerous modifications and variations in practice of the invention are expected to occur to those skilled in the art upon consideration of the foregoing detailed description of the invention. Consequently, such modifications and variations are intended to be included within the scope of the following claims. 

1. A clathrate comprising ClO₂.
 2. The clathrate of claim 1, wherein the clathrate includes at least 0.1 weight % ClO₂, based on the weight of the clathrate.
 3. The clathrate of claim 2, wherein the clathrate includes from 0.1 to 10 weight % ClO₂, based on the weight of the clathrate.
 4. The clathrate of claim 3, wherein the clathrate includes from 0.4 to 3 weight % ClO₂, based on the weight of the clathrate.
 5. The clathrate of claim 1, wherein the clathrate is a reaction product of a compound selected from the group consisting of monosaccharides, disaccharides, polysaccharides and mixtures thereof and organic acid.
 6. The clathrate of claim 5, wherein the monosaccharide is selected from the group consisting of glucose, ribose, fructose, galactose, sorbose, tagalose, allose, altrose, mannose, gulose, idose, galactose, talose and mixtures thereof.
 7. The clathrate of claim 6, wherein the clathrate includes at least 9 weight percent monosaccharide, based on the weight of the clathrate.
 8. The clathrate of claim 6, wherein the clathrate includes from 9 to 74.5 weight % monosaccharide, based on the weight of the clathrate.
 9. The clathrate of claim 8, wherein the clathrate includes from 20 to 70 weight % monosaccharide, based on the weight of the clathrate.
 10. The clathrate of claim 6, wherein the monosaccharide is glucose.
 11. The clathrate of claim 5, wherein the disaccharide is selected from the group consisting of sucrose, maltose, lactose and mixtures thereof.
 12. The clathrate of claim 5, wherein the organic acid is selected from the group consisting of citric acid, ascorbic acid, lactic acid, tartaric acid, boric acid and mixtures thereof.
 13. The clathrate of claim 5, wherein the clathrate includes at least 25 weight percent organic acid, based on the weight of the clathrate.
 14. The clathrate of claim 5, wherein the clathrate includes from 25 to 80 weight % organic acid, based on the weight of the clathrate.
 15. The clathrate of claim 12, wherein the organic acid is citric acid.
 16. The clathrate of claim 5, wherein the polysaccharide is selected from the group consisting of cellulose, starch and mixtures thereof.
 17. The clathrate of claim 1, wherein the organic acid/saccharide blend is further blended with 0 to 4 weight percent surfactant, based on the weight of the clathrate.
 18. The clathrate of claim 17, wherein the surfactant is Tergitol or Triton.
 19. The clathrate of claim 1, wherein the organic acid/saccharide blend is further blended with 0 to 3 weight percent EDTA, based on the weight of the clathrate.
 20. The clathrate of claim 1, wherein the clathrate is coated with a polymer.
 21. A clathrate of claim 1, wherein a solvent consisting of alcohols, ethers, oils and mixtures thereof is added to increase the concentration of ClO₂ in the clathrate.
 22. A method for forming a clathrate of ClO₂, the method comprising: blending at least 25 weight percent organic acid, based on the weight of the clathrate, with a saccharide to form a organic acid/saccharide blend; and contacting the organic acid/saccharide blend with a source of ClO₂.
 23. The method of claim 22, wherein the source of ClO₂ is ClO₂ gas.
 24. The method of claim 22, wherein the source of ClO₂ is a salt of ClO_(x), where x is 1, 2, 3 or
 4. 25. The method of claim 24, wherein the salt is selected from the group consisting of Na, K, Ca, Mg and mixtures thereof.
 26. The method of claim 22, wherein the method is effective for providing a clathrate includes at least 0.1 weight % ClO₂, based on the weight of the clathrate.
 27. The method of claim 22, wherein the clathrate includes from 0.1 to 10 weight % ClO₂, based on the weight of the clathrate.
 28. The method of claim 27, wherein the clathrate includes from 0.4 to 3 weight % ClO₂, based on the weight of the clathrate.
 29. The method of claim 22, wherein the saccharide is selected from the group consisting of monosaccharides, disaccharides, polysaccharides and mixtures thereof and organic acid.
 30. The method of claim 29, wherein the monosaccharide is selected from the group consisting of glucose, ribose, fructose, galactose, sorbose, tagalose, allose, altrose, mannose, gulose, idose, galactose, talose and mixtures thereof.
 31. The method of claim 30, wherein the clathrate includes at least 9 weight percent monosaccharide, based on the weight of the clathrate.
 32. The method of claim 30, wherein the clathrate includes from 9 to 74.5 weight % monosaccharide, based on the weight of the clathrate.
 33. The method of claim 32, wherein the clathrate includes from 20 to 70 weight % monosaccharide, based on the weight of the clathrate.
 34. The method of claim 30, wherein the monosaccharide is glucose.
 35. The method of claim 29, wherein the disaccharide is selected from the group consisting of sucrose, maltose, lactose and mixtures thereof.
 36. The method of claim 29, wherein the organic acid is selected from the group consisting of citric acid, ascorbic acid, lactic acid, tartaric acid, boric acid and mixtures thereof.
 37. The clathrate of claim 29, wherein the clathrate includes at least 25 weight percent organic acid, based on the weight of the clathrate.
 38. The method of claim 29, wherein 25 to 80 weight % organic acid is blended with saccharide and organic acid.
 39. The method of claim 36, wherein the organic acid is citric acid.
 40. The method of claim 29, wherein the polysaccharide is selected from the group consisting of cellulose, starch, and mixtures thereof.
 41. The method of claim 22, wherein the organic acid/saccharide blend is further blended with 0 to 4 weight percent surfactant, based on the weight of the clathrate.
 42. The method of claim 41, wherein the surfactant is Tergitol or Triton.
 43. The method of claim 22, wherein the organic acid/saccharide blend is further blended with 0 to 3 weight percent EDTA, based on the weight of the clathrate.
 44. The method of claim 22, wherein the clathrate is coated with a polymer.
 45. A method of claim 22, wherein a solvent consisting of absolute alcohols, ethers, oils and mixtures thereof is added to increase the concentration of ClO₂ in the clathrate.
 46. A method of claim 22, wherein a desiccant is added to the ClO₂ to remove water during storage.
 47. A method for treating an aqueous composition, the method comprising contacting the aqueous composition with a clathrate of ClO₂, the method effective for reducing a microbial count in the aqueous composition by at least five logs.
 48. The method of claim 47, wherein the clathrate of ClO₂ is effective for providing a concentration of ClO₂ in the aqueous composition of at least 0.2 ppm.
 49. A method of claim 47, wherein ClO₂ gas is released from the clathrate structure by heating in excess of 37° C.
 50. A method of claim 47, wherein ClO₂ gas is released from the clathrate structure by dissolution in water or an aqueous containing media.
 51. A method of claim 47, wherein ClO₂ gas is released from the clathrate at a water level of at least 0.5 weight percent, based on the weight of the clathrate.
 52. A method for forming a ClO₂ comprising: irradiating a xClO₂ solution with a UV source for a time and intensity effective for forming ClO₂, wherein x is Na, K, Ca or Mg; and recovering ClO₂ with aeration.
 53. The method of claim 52, wherein the UV irradiation has an intensity of at least 263 nm at 60 microamps at 5000V.
 54. A method for forming ClO₂ comprising: combining a stream of RClO₂ and an acid stream in an amount effective for providing an R ion concentration equivalent to an acid concentration, wherein R is Na, K, Ca or Mg; irradiating the streams with a UV source for a time effective for forming ClO₂; removing the UV source from the streams; and recovering ClO₂.
 55. The method of claim 54, wherein UV irradiation is applied for at least one minute.
 56. The method of claim 54, wherein the UV irradiation has an intensity of at least 4,000 microowatts/square centimeter. 